Machines for operating upon margins of workpieces



H. w. WEEKS 3,088,144

MACHINES FOR OPERATING UPON MARGINS 0F WORKPIECES May 7, 1963 4 Sheets-Sheet 1 Filed April 18, 1961 fnz/emar HoraceWh/eeks By his Aziorney M W y 7, 1963 H. w. WEEKS 3,088,144

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Siroke Bz'cmbpell B Q T T g "T E P ToPraamplz'fier" United States Patent 3,088,144 MACHINES FOR OPERATING UPON MARGINS OF WORKPIECES Horace W. Weeks, Dayton, Ohio, assignor to United Shoe Machinery Corporation, Boston, Mass., a corporation of New Jersey Filed Apr. 18, 1961, Ser. No. 103,744 11 Claims. (Cl. 12--55.1)

This invention relates to machines for progressively operating automatically on the margins of work pieces, and is more particularly concerned with the provision of improved means for automatically guiding and acting on the irregularly curved edges of sheet material. The invention is herein illustrated as embodied in a machine for folding the edges of shoe uppers to provide them with an attractive, finished appearance. It is to be recognized that in various aspects application of the invention is not thus limited.

In operating many machines proper manual direction and advancement of individual work pieces, especially those which are flexible and irregularly shaped, is tedious and often inaccurate. Accordingly as disclosed in an application for United States patent, Serial No. 94,556, lled March 9, 1961, in the name of John E. Clemens et al., and in an application for United States patent, Serial No. 827,970 filed July 17, 1959, in the name of H. F. Schaefer, Jr., et al., now Patent No. 2,979,745, work guidance mechanism has been designed for automatically determining the operating path of a tool in accordance with controlling curvature, such as that of the edge of V the work to be processed, thereby relieving an operator of considerable routine care. While the work steering means in each of these disclosures is responsive to a curvature sensing circuit, the Clemens et al. arrangement embodies a torque exerting mechanism operative at only a single locality to turn the work about successive work engaging positions of an operating tool, and the Schaefer et al. approach involves a pair of spaced work engaging members which are respectively reversible and have velocities the ratios of which are fixedly proportionate to the curvature of the margin being operated upon. It is recognized that automatic guidance of work is broadly old, especially in the machine tool field, but it is particularly to be noted that the novel guidance concepts referred to and hereinafter further explained are more especially adapted for use on lighter work, especially sheet material, and are readily distinguished in that the steering means, in lieu of moving a work carriage for instance, is advantageously arranged to act directly on the work itself.

The peripheral operation selected for present purposes of illustration of this invention is that of edge folding, a technique in which the margin of sheet material, such as fabric or leather or the like, is folded back and secured upon itself to create a new, smooth, and attractively finished edge. The Schaefer et al. disclosure referred to above likewise teaches the combination with an edge folding mechanism of automatic means for guiding the work to such mechanism. It is a primary object of the present invention, however, to provide a simple and further improved machine, for instance of the edge folding type, wherein the operating instrumentalities are advantageously disposed in combination with novel automatic work guidance means and certain auxiliary controls additionally insuring quality performance on a greater variety of work.

In keeping with the object just stated, a feature of the invention resides in the provision, in combination with a work support, an operating instrumentality adapted to act on the margin of a work piece, and a work feeding ice mechanism, of means including a work steering member for guiding the work piece automatically as it is fed past said instrumentality, said guiding means comprising a presser unit which is synchronously cooperative with both the work steering member to generate a turning moment and with the instrumentality to create a center about which the turning moment may move the work. It will be recognized that in some aspects the work guidance means herein disclosed resembles that described and claimed in the copending Clemens et a1. application above cited. Thus the steering member is in each case shown as a servo-controlled work engaging wheel having a velocity corresponding to the marginal curvature of the work as sensed in a locality close to, but just ahead of, the operating instrumentality. For determining the wheel velocity, the curvature is, moreover, preferably sensed electrically as hereinafter disclosed by means of a circuit including a light sensitive device arranged at one side of the work to respond to rays beamed from a source on the opposite side and passing the margin of the work in a locality just ahead of the operating instrumentality. The latter is herein exemplified in the form of a creaser against which a conventional, oscillatory folding finger is moved to fold successive marginal portions of the work. These successive portions are illustrated as being fed in translation and step by step by means of the usual oscillatory, cooperative hammer and anvil feeding mechanism which is also employed, as customary, to press the fold formed by the creaser and folding finger. Contributing markedly to simplifying an otherwise crowded machine organization as well as enhancing its reliability, the automatic Work guidance means, though shown as being continuously operative, is made effectively to alternate with feeding movements of the hammer and anvil, the guidance means including a camactuated presser unit. The latter consists of a roll arranged to cooperate with the steering wheel and an arm carrying the roll and arranged to cooperate with the creaser. Positive actuation of the presser unit accordingly is such that in each interval that the feeding mechanism is inoperative to feed and press a folded marginal portion, the steering wheel with the aid of the roll is enabled to exert a torque on the work properly to turn it bodily about an instantaneous center simultaneously established at the foot of the creaser where the Work is being momentarily clamped for the purpose by the presser unit arm. It will be appreciated that in selected embodiments of the invention it may be preferable to provide an independent abutment (in lieu of employing any portion of an operating instrumentality such as a creaser foot) for creating a turning center.

Further to relieve an operator of the burden of continuous, close attendance during operation of the machine, certain functions hitherto requiring his control or decision have now been rendered subject to automatic control.

Thus a further feature of the invention as shown in the exemplary machine comprises, in combination with automatic work guidance means of the type aforementioned, control mechanism including a circuit having a light sensitive device disposed to be covered by the work when its margin is first presented to the curvature sensing means referred to above, the control mechanism thereby being actuated (I) initially to lower the steering wheel into its operating position and (2) to initiate the flow of cement to the folding locality via an outlet formed in the creaser. Additionally, control circuitry is advantageously provided wherein light sensitive devices are disposed ahead of the operating zone and respectively responsive automatically to shorten feeding increments in traversing outside curvature wherein the radius of curvature is less than a predetermined distance, and to initiate a margin snipping cutter for facilitating traversing inside curvature wherein the radius of curvature is less than a predetermined distance.

The above and other features of the invention, together with various novel details of construction and combinations of parts, will now be more particularly described in connection with an illustrative embodiment thereof and with reference to the accompanying drawings in which:

FIG. 1 is a view in side elevation of a machine exemplifying the invention, frame portions being cut away to reveal internal mechanism;

FIG. 2 is an enlarged view of the operating instrumentalities shown in FIG. 1 with automatic work guidance mechanism in operative position and being shown in section to reveal construction details;

FIG. 3 is an end elevation of operating elements shown in FIG. 2 and indicating the relative position of a presser unit of the guidance mechanism;

FIGS. 4-7, inclusive, are diagrammatic plan views illustrating successive positions of a portion of an upper of a shoe as it is sensed by a guidance cell and associated light responsive controls;

FIG. 8 is a left-hand elevation of shaft positioning means for controlling stop positions of the several instrumentalities;

FIG. 9 is a plan view of the presser unit shown in FIGS. 2 and 3; and

FIG. 10 is an electrical diagram of the machine.

The invention is herein shown as embodied in a Cementing and Folding Machine of the type disclosed basically in United States Letters Patent No. 2,270,891 on an application of C. A. Newhall and more recently improved as illustrated in United States Letters Patent No. 2,720,667, granted October 18, 1955 on an application of W. E. Naugler. In view of the complete descrip tion and illustrations therein, only so much of that machine is described below as is essential to a full understanding of the present invention, FIG. 1 largely corresponding with FIG. 1 of the Naugler patent.

A hollow base 10 of the machine has an arm 12 provided with a removable end portion 14 on which is secured a work supporting plate 16. A cap 18 (FIG. 1) mounted on the base has a neck 20 overhanging the arm 12 and terminates in a removable head 22. The operating instrumentalities, other than automatic work guidance means generally designated 24 (FIGS. 1 and 2) later to be described, largely resemble those of the earlier mentioned construction in form and mounting and comprise a gage block 26 for deflecting upwardly the margin to be folded, a gage finger 28, and a folding finger 30 for folding the margin of the work against a creaser foot 32. In conventional manner a hammer 34 (FIGS. 1 and 2) cooperates with an anvil 36 to press the fold when it has been formed, the hammer and anvil acting together to feed the work rectilinearly a step at a time past the gage block 26 and away from the observer in FIGS. 1 and 2. A snipper knife 40, operable on sharply incurved margins of the work, also is provided, its actuating mechanism being essentially as shown in the Naugler patent referred to above but subject to improved control means hereinafter explained.

For automatically guiding the margin of a work piece, for instance that of an upper U (FIGS. 4-7 inclusive), to the work zone of the operating instrumentalities mentioned, the means 24 comprises a single, continuously operative steering wheel 42 (FIGS. 1, 2 and 3) herein shown as being reversibly rotatable on a fixed horizontal axis and having a work engaging perimeter 44. This perimeter is preferably serrated and disposed to contact the upper surface of the work at a locality inwardly of its margin and substantially opposite to the cooperative hammer and anvil, or more precisely, opposite to the point from which they commence their feeding strokes, as III-1 dicated in FIG. 3, the margin then being deflected upwardly by the gage block 26 to the extent of the fold width as determined by the gage finger 28. Additionally, the guidance means 24 comprises a presser unit generally designated 46 (FIGS. 2-4 and 9) operative heightwise in a slot of the plate 16 and by means of which the velocity of the wheel 42 is caused, in the intervals in which the hammer and anvil are inoperative to feed, to exert an appropriate steering torque on the work. For this purpose, much as in the Clemens et al. copending application above cited, the Wheel 42 is driven by a curvature sensing circuit later to be explained which is responsive to the change in curvature of the edge of the work at a point close to, but just ahead of, the gage block 26 in the work zone. The unit 46 includes a presser roll 48 cooperative with the perimeter 44 and a rocker arm 50 by which the roll is carried heightwise, the arm having an upstanding portion 52 formed and arranged to serve intermittently as a pivot for the work when the latter is bodily turned thereon by reason of the cooperation of the wheel 42 and the roll 48. The pivot portion 52, it may be noted, corresponds in part with an element termed a gripper in the cited Naugler patent and is similarly actuated, by means about to be described for intermittently pressing the work against the under side of the creaser foot 32. The functional aspect shared by both the pivot portion 52 and the gripper element referred to is that of holding the work against rectilinear movement during the folding of successive marginal portions; while the gripper in the earlier disclosure also held the work against rotary movement in the intervals of folding, it should be noted by way of contrast that the pivot portion 52 in the present disclosure serves to create a turning center for the work at the locality of its contacts with the creaser foot and with the portion 52 thereby permitting angular translation as required to remove any error signal from the guidance means 24.

The creaser foot 32, as in the Naugler construction referred to, is heated and provided with a passageway (not shown) for delivery of adhesive to be applied to the work immediately prior to the folding operation. The adhesive is supplied from a receptacle 54 (FIG. 1) and exuded from a beveled face of the creaser foot for coating of the under side of the upturned lip of the margin, the flow being controlled by a valve 56 (FIGS. 1 and 2) actuated by a Bowden wire 58 operable by a solenoid 60 further referred to hereinafter. It will be recognized that in applying this invention to organizations wherein no instrumentality (such as the creaser foot) is available to mad with the portion 52 to provide a turning center, an abutment should be incorporated for this purpose.

For operating the presser unit 46 (and hence effectively operating the guidance means 24) in proper time relation to the operation of the feeding and operating instrumentalities, use is made of actuating mechanism disclosed in the Naugler patent. A main shaft 62 (FIGS. 1 and 2) journaled in the base 10 and the arm 12 is provided with a pulley 64 that is connected by a belt 66 to a motor 68 (FIG. 10). The rocker arm 50 (FIGS. 2 and 3) is mounted on the outer end of a rock shaft 70 journaled in the arm 12 and parallel to the shaft 62. A release arm 72 (corresponding to the arm 50 in the Naugler patent) is secured to the inner end of the shaft 70 and forms means by which it may be rocked by an operator to lower the presser unit 46 when desired. The release arm 72 ('FIG. 1) has a downwardly extending portion having a rounded cam follower end 74 arranged to engage a cam 76 (FIGS. 1 and 3) mounted on the shaft 62. The cam 76 is integral with a collar 78 adjustably secured by a pinch screw 80 to the shaft 62, and a spring 82 (FIG. 3) in the arm 12 normally maintains engagement of the portion 74 with the cam 76 so that rotation of the shaft 62 will cause the presser roll 48 and the pivot portion 52 substantially simultaneously to move into and out of engagement with the under side of the upper U being guided in the machine. By adjusting the collar 78 with respect to the shaft 62 movements of the presser unit 46 may be varied in a cycle of operations. For imparting steering torque to the work when it is engaged by the presser roll 48 and is thereby urged against the perimeter 44, the wheel 42 is continuously driven by a curvature sensing circuit including a servo motor 84 (FIGS. 2 and responsiveto a light sensitive device herein shown as a guidance solar cell 86 (FIGS. 47) removably mounted on a level with the upper surface of the work supporting plate 16, the cell 86 being preferably in a detachable plate 88 and disposed transversely of the rectilinear feed effected by the hammer and anvil and immediately ahead of the gage block 26. Preferably the arrangement is such that a mid point of the cell 86 substantially coincides with a null line parallel to the direction of zero error feed, or explained in other words, the cell is disposed transversely of the general direction of feed effected by the hammer and anvil so that, when the operating locality of the upper is correctly oriented with respect to the gage block 26, about one-half of the cell is covered by the work acting as a shutter, and the other half of the cell is exposed to light focused from an incandescent source shown herein as a lamp 90 (one only shown in FIGS. 1 and 2 but two adjacent lamps preferably being employed) bracketed to the head 22.

' 'In the curvature sensing circuit, which is essentially as described more fully in the Clemens et al. application referred to above, a DC. voltage is generated in the cell -86 when it is more or less covered by reason of a change in marginal curvature in that locality of an upper approaching the block 26. Accordingly this voltage is directed to a preamplifier unit 92 (FIG. 10) and, opposed by voltage from a bias supply 94, creates a net voltage difference constituting an error signal. The voltage phasing of thissignal by known means provides proper direction of rotation information for the servo motor 84, and the output of the preamplifier unit 92, after being amplified in a servo amplifier unit 96, is fed to the motor 84. In known manner, the pure error signal is modified for damping purposes by a tachometer (not shown).

For driving the steering wheel 42 the servo motor is mounted on a casing 98 (FIG. 2) bracketed to the head 22 and has an output shaft coupled to reduction gearing (not shown) in a housing 100 fixedly secured by screws 102, 102 to the base of the casing. A vertical output shaft 104 depends from the reduction gearing and is formed with a diametric slot 106 for slidingly receiving a coupling pin 108 in the upper end of a rotary spindle 110. The latter is journaled in spaced bearings112, 112 mounted in a depending core 114. The lower end of the spindle has bevel gear connection to a stub shaft 116 journaled in a right-angle gear box 118 threaded on the core :114 and carrying the steering wheel 42.

As shown in FIG. 2 the machine is at rest and the wheel 42 is in its lower, operative position. The wheel 42 is raised automatically before starting the machine to permit introduction of a work piece to be edge folded, and for subsequent work ejection. For this purpose a solenoid 120 (FIGS. 2 and 10) secured to the casing 98 is deenergized by initial presentation of a margin of the work to cover a light sensitive cell 122 (FIGS. 47 and 10) which is also mounted in the plate 88 and adapted to control cement flow as will be explained. The solenoid core 114 is slidable axially on a sleeve 126, and the lower limit of movement of the cone is determined by an inward flange of a retainer nut 128 threaded onto the solenoid 120. On being energized the solenoid raises its core 114 and consequently the wheel 42 against the resistance of a return spring 130. An upper end of the latter abuts the housing 100 and a lower end bears on a collar 132 carried by the inner ends of screws 134, '134 which are threaded radially through a collar 135 slidable on the core 114 and respectively extend through vertical slots 138 formed in the sleeve 126. These screws and slots serve also to hold the core and hence the wheel 42 against movement about a vertical axis but still allow the wheel 42 to move vertically when a variation in work thickness is encountered. A nut 136 threaded on the core 114 bears against the collar and thereby controls the steering wheel pressure against the work.

Referring to FIG. 10, and assuming the motor 68 has been started by closure of a motor switch 140 and a treadle switch 142, the initial presentation of the upper to the machine removes a signal from the covered cell 122 and accordingly a relay K1 is deenergized to close contacts K181, KllBZ, and K1136, and open a contact KlAl. A time delay relay K2 is thereby energized through the contact K1132 and, after a fixed time delay, opens a contact K2B1 to deenergize the solenoid 120 and thus lower the wheel 42 into operating position. The time delay is sufiicient to permit the margin of the work to be introduced thereunder and over the roll 48, for engagement with and deflection by the gage block 26. At the same time the closure of the contact K133 energizes the solenoid 60 whereby the valve 56 is opened to initiate the flow of adhesive through the creaser foot. If it is desired to run the machine continuously, incidentally, in lieu of using the treadle switch 142, a push button PB may be depressed for starting the motor 68 and again depressed to stop it. For facilitating more uniform edge folding and obtaining a neatly finished product with a minimum of effort on the part of the operator, the control plate 88 has additionally embedded therein, at opposite sides of the line of rectilinear or no error feed, a device sensitive to the light source 90 and shown as a solar cell 1 46 (FIGS. 47 and 10), and another device sensitive to the same source and shown herein as a solar cell 148 (FIGS. 47 and 10). These cells are disposed ahead of the cells 86 and 122. The cell 146 is so positioned that, upon being covered at least partially by an incurved marginal portion as shown in FIG. 7, it is effective through its transistor amplifier 147 (FIG. 10) to energize a relay K3 and thus close a contact K3A1 for energizing a solenoid 150' (FIG. 1). As a result the snipper knife '40, instead of being under operator control as hitherto, is now automatically caused to cooperate with the gage block 26 in shipping more inwardly curved portions of the margin. It will be understood that for this purpose a plunger .152 of the solenoid 150* corresponds with a treadle rod designated 410 in said Naugler Patent, interconnecting means for operating the snipper knife remaining essentially as fully disclosed therein. The cell 14 8 advantageously supplants a manually operable means (including a treadle rod 182, etc., in the Naugler patent) for changing the length of feed and folding increments imparted by the oscillations of the hammer and anvil. Thus, upon a marginal portion of outside curvature approaching the operating zone, as shown in FIGS. 5 and 6, the cell 148 becomes sufficiently uncovered to emit a voltage signal via its transistor amplifier 154 (FIG. 10) whereby a relay K6 is energized to close a contact K6A1. As a consequence, a solenoid 156 (FIG. 1) acts on an arm 158 (against a return spring not shown) to rotate a feedcontrol shaft 160* and hence automatically shorten the feeding increments appropriately for the interval in which the outside curvature is being folded.

As illustrated in FIG. 8, the machine is preferably provided with means generally designated for positioning the main shaft 62 at the termination of each machine operation so that the finger 30 will be in its down position and the hammer and anvil will then be released from the work and separated heightwise to permit its withdrawal and subsequent presentation of the next work piece to be edge folded. This shaft positioning means is briefly described here since it corresponds largely with the structure fully explained and disclosed in the Clemens et al. application above cited and is representative of various shaft positioning mechanisms which may be used. A variac 182 (FIG. 10) changes AC. voltage applied to a rectifying bridge 186 which, in turn, provides a DC. voltage to the motor 68 as selected for controlling its forward speed. The motor 68 is energized by closure of the switch 142 to energize relays K4 and K5, resultant AC. voltage being applied to a rectifier bridge 186 through a contact KSAI and directed as DC. voltage through contacts K4A1 and K4A2 to the motor. When the foot switch 142 is released, a reversing DC. voltage is applied to the motor 68; then upon opening of a switch 183 by the means 180 as next described the AC. voltage to the bridge cuts off and stops the motor to stop the shaft 62 in the desired position. Secured on this shaft is a cam 190 (FIG. 8) having a rise over a 60 arc. The cam is straddled by a cam plate 192 radially slidable in a guideway 194 formed in a guide plate 196, the latter being aflixed to the pulley 64. During forward or folding operation the torque required to rotate the shaft 62 reacts on the cam plate 192 causing it to retract radially inward, and when fully retracted a fiat of the cam engages the plate 196 internally in fixed driving relation. On opening the switch 142 the relays K4 and K5 are deenergized, and a relatively low AC. voltage is accordingly applied to the rectifier bridge 186 through a now closed contact K5131 (FIG. This gives rise to a DC). reversing voltage being applied to the motor 68 through now-closed K4B1 and K4132. Accordingly, when the machine has stopped and its shaft 62 starts to reverse (in counter-clockwise direction indicated in FIG. 8), the cam plate 192 is radially displaced outwardly until its projection 198 engages the upper end of a lever 200 pivoted at 202 on a bracket 204 afiixed to the machine frame. This engagement pivots the lever 200 clockwise as viewed in FIG. 8 against resistance of a spring 2&6 and hence opens the switch 188 to stop the motor and its shaft 62 in proper position. A stop pin 208 in the bracket 204 cooperates with the spring 206 in determining the normal inoperative position of the lever 200.

From the foregoing it will be clear that this invention provides a machine for performing marginal operations, for instance edge folding, expeditiously and with little burden on the operator other than to present and remove successive work pieces. In presenting an upper U, after closing the switch 142 to start the motor 68 and hence commence actuation of the rectilinear feeding means and operating instrumentalities, the cell 122 is covered automatically causing the steering wheel 42 to be lowered after a suitable time delay during which it is possible to admit the margin about half way over the guidance cell 86 and against the gage 26 and the finger 28, and the valve 56 to be opened for the flow of adhesive to the margin about to be folded. The presser roll 48, due to the cam 76, is elevated intermittently together with the pivot portion 52 into effective work engaging or steering relation with the under side of the upper. These steering engagements are thus caused to alternate with the rectilinear feeding steps effected by the hammer and anvil, torque being imparted as continuously directed by the servo motor in accordance with the guidance signal derived from the cell 86, intermittently to swing the upper bodily about the turning center which is created by the cooperating localities of the creaser foot 32 and the presser portion 52. In this manner steering error is continuously being reduced to zero and a uniform width of folded margin is obtained which corresponds with the initial contour of the unfolded margin.

During the automatic guidance of a work piece the cell 146 serves automatically to actuate the shipper 40 as needed on sharper inside marginal curvature, and the cell 148 serves automatically to shorten the feeding and folding increments as required for successfully negotiating the sharper outside marginal curvature. If for any reason it is desirable promptly to remove a work piece from the machine a kick out switch 210 (FIG, 10) may be manually closed, thus deenergizing the solenoid 60 to stop the flow of adhesive and energizing solenoid to discontinue automatic guidance thus enabling the hammer and anvil simply to feed the work margin directly out of the work zone.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine having a tool adapted to operate on successive marginal portions of a work piece, mechanism for feeding the work piece past the tool, and guidance means including a movable member for steering the work piece automatically, as it is fed, in accordance with the curvature of the margin to be operated upon, said guidance means comprising a presser having work engaging portions one of which is arranged to cooperate with the member to exert a turning moment and another of which is cooperative with the tool to determine successive centers about which the turning moment can act to guide the work piece.

2. In a machine having a tool for operating along the margin of a work piece, a work support, an abutment adjacent thereto, mechanism for feeding the work piece on the support in translation past the tool and the abutment, guidance means including a curvature sensing circuit responsive to change in edge curvature of the work piece at a locality ahead of the tool and a steering wheel controlled by the circuit and engageable with the work piece inwardly from the tool, a pair of presser feet mounted for movement heightwise relative to the support for spaced engagements with the work piece and cooperation, respectively, with the wheel and with the abutment, and means for simultaneously effecting such engagements of the presser feet in time relation to said feeding mechanism.

3. In a machine having a movable member for exerting steering torque on a work piece and an adjustable abutment against which the work piece may be pressed to provide a turning center for said torque, curvature sensing means for controlling the velocity of said member, mechanism for feeding the work piece step by step in translation, and presser means synchronously cooperative with the member and abutment during non-operation of the feeding mechanism for causing the work piece to be turned bodily about said center, said presser means having a cam actuated driving connection to said feeding mechanism.

4. In a machine having an edge finishing tool and an abutment adjacent thereto, mechanism for feeding a work piece past the tool and beneath the abutment, means including a reversible torque exerting member for automatically steering the work piece about a turning center on the abutment as the work is fed with respect to the tool, said means including a presser unit having spaced portions arranged to press successive localities of the work piece into engagement, respectively, with the member and said abutment, and power means for cyclically changing the pressure of such engagements whereby the work piece is intermittently swung about said center.

5. In an edge folding machine, a work support, edge folding means including a work engageable creaser having an outlet for adhesive, mechanism for feeding a work piece on the support in translation and intermittently past the creaser, guidance means including a work engageable wheel for automatically steering the work piece with respect to the folding means according to the curvature of the margin of the work piece in a locality ahead of the creaser, said guidance means including a first light sensitive device arranged on the support for sensing said curvature, valve means for controlling the supply of adhesive to the creaser outlet, and a control circuit including a second light sensitive device disposed to be covered by the work piece when its margin is first presented to the first light sensitive device whereby the wheel is automatically shifted into its work engaging position and said valve means permits the flow of adhesive through the creaser.

6. In work guidance mechanism of the class wherein a movable member is frictionally engageable with the work to apply torque for steering it bodily about the work contacting locality of an operating tool spaced from the member, the combination with said mechanism of a drive shaft rotatable to feed the work in a cycle of operation in translation past the tool, and cam actuated means controlled by said shaft for timing the effective and ineffective operation of the steering member in each cycle.

7. In a machine having a tool adapted to operate on the margin of a work piece and of the type having automatic means for feeding and guiding the margin in increments to the tool, said means including a first device on one side of the work piece responsive to light from a source on the other side thereof, a second device ahead of the first device and responsive to light from said source, and a control circuit including the second device for automatically changing the increments of feed as curvature of the margin changes.

8. A machine as set forth in claim 7 further characterizing in that the second device is arranged with respect to the first to shorten the feeding increments to facilitate operation upon marginal portions of outside curvature having at least a predetermined radius of curvature, an instrumentality is provided for operating on marginal portions having inside curvature, and a third device responsive to light from said source is arranged automatically to actuate said instrumentality.

9. In an edge folding machine of the type having an edge gage block and step by step means for feeding the margin of a work piece on a work support past said block, a control plate removably mounted in said support, automatic work guidance means including a first light sensitive device in the plate disposed immediately ahead of the gage block, a tool adapted to act on incurved portions of the margin to be folded, a second light sensitive device disposed in the plate ahead of the first device for automatically actuating the tool, and a source of light to which the devices are responsive, respectively, upon relative light-intercepting movement of the margin.

10. In an edge folding machine of the type having an edge gage block and a hammer and anvil movable to feed the margin of a work piece step by step past the block, a work support, a source of light above the support and focused on an operating zone of the support just ahead of the block, automatic work guidance means including a first light sensitive device in said zone immediately ahead of the block, a second light sensitive device in said zone farther ahead of the block, and means responsive to the second device upon relative shutter movement of a margin to be folded for causing the hammer and anvil automatically to change the length of feed steps.

11. In a machine of the kind having an edge gage for turning the margin of work to be edge folded, and comprising means for intermittently feeding the work step by step past the gage, a creaser against which the turned margin is folded and through which adhesive is delivered to the margin before it is folded, and automatic work guidance means including a continuously operative steering wheel arranged yieldingly to engage the work inwardly from the creaser, the combination with a presser unit cooperative with the steering wheel and the creaser to cause the work to be guided in the non-operating intervals of the feeding means, of means responsive to initial presentation of the work toward the gage to admit the margin between the wheel and the presser unit and initiate delivery of the adhesive and in the absence of the margin to discontinue delivery of the adhesive.

References Cited in the file of this patent UNITED STATES PATENTS 2,259,502 Topham et al. Oct. 21, 1941 2,270,891 Newhall Jan. 27, 1942 2,720,667 Naugler Oct. 18, 1955 2,849,734 McGahan Sept. 2, 1958 2,979,745 Schaefer et al. Apr. 18, 1961 

1. IN A MACHINE HAVING A TOOL ADAPTED TO OPERATE ON SUCCESSIVE MARGINAL PORTIONS OF A WORK PIECE, MECHANISM FOR FEEDING THE WORK PIECE PAST THE TOOL, AND GUIDANCE MEANS INCLUDING A MOVABLE MEMBER FOR STEERING THE WORK PIECE AUTOMATICALLY, AS IT IS FED, IN ACCORDANCE WITH THE CURVATURE OF THE MARGIN TO BE OPERATED UPON, SAID GUIDANCE MEANS COMPRISING A PRESSER HAVING WORK ENGAGING PORTIONS ONE OF WHICH IS ARRANGED TO COOPERATE WITH THE MEMBER TO EXERT A TURNING MOMENT AND ANOTHER OF WHICH IS COOPERATIVE WITH THE TOOL TO DETERMINE SUCCESSIVE CENTERS ABOUT WHICH THE TURNING MOMENT CAN ACT TO GUIDE THE WORK PIECE. 